The lack of undo entries when manipulating Splines with Maxscript is still a long lasting problem.
In my opinion 3ds max got very good Spline editing capabilities, which can be expanded with custom tools. But such tools are significantly limited by the fact that whatever operation is performed by scripted tools won't generate an Undo entry, and scripters are forced to build their own workarounds to provide some kind of undo feature.
Considering this lack of undo seems to stretch back more than a decade, if 3ds max ever had undo for scripted spline manipulations that is, I'd say it's finally time to add this elementary feature to 3ds max.
